The invention pertains to a cooling unit for refrigerators in particular, which are to be operated without noise and for which a heat source is to be used as drive.
From U.S. Pat. No. 3,782,134, an absorption cooling system is known in which almost all components are built in two plates one put on top of the other, in which lines for the absorber, the generator, the condenser and the evaporator are provided for. This results in easy manufacture of the absorption cooling system, but has the drawback that the efficiency of the cooling circuit is reduced. On the warm side of the circuit in particular, losses occur, because in the plates thermal conduction takes place between the individual components, the generator is not built as efficient double-pipe generator and only a heat exchanger with lower efficiency is provided for between the generator and the absorber. The rigidly assembled absorption cooling system furthermore has to be kept in a given position for operation, for avoiding banking of liquid in one of the lines. Use of this system in a vehicle parked on inclined area or in a boat in which inclination may occur, too, thus is not appropriate.
In addition, it is known from EP 0 642 762 to operate a cooling unit using an absorption circuit in which the absorber is formed by two plates arranged in parallel in which lines are formed. In the absorption circuit rich solution at first is supplied on the bottom side of the absorber to a heat exchanger and subsequently to a generator. NH.sub.3 vapor is expelled from the generator built as double pipe and is supplied to a condenser. The condensate thereafter is evaporated in an evaporator, therein heat being abstracted from the environment for cooling purposes. The vaporous medium subsequently is supplied to the absorber where it again is absorbed by the liquid supplied from the generator. It is true that the described system for standard operation has a comparatively good efficiency in terms of energetic, however, as soon as the cooling unit is inclined the danger exists that the liquid contained in the absorber collects and the liquid is banked in the horizontally arranged lines such that a siphon is created. Such banking of liquid severely impedes operation of the cooling unit and subsequently reduces efficiency of the system. Moreover, the system shown in EP 0 624 762 is of expensive construction, since the absorber, the generator, the condenser and the evaporator each are built separately and, therefore, have to be assembled in a complicated installation process.